%%
%% The LaTeX Companion, 3ed
%%
%% Example 8-2-23 on page I-601 in "Image inclusion revisited".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{159.0pt}

%StartShownPreambleCommands
\usepackage{subcaption,adjustbox}
\newcommand\fitimage[1]
               {\adjustimage{width=\linewidth}{#1}}
%StopShownPreambleCommands

\begin{document}
\begin{figure}
  \centering
  \subcaptionbox{A large cat}[.4\linewidth]
                {\fitimage{cat}}
  \qquad
  \subcaptionbox{A small elephant}[.4\linewidth]
                {\fitimage{elephant}}
  \caption{Two animals}
\end{figure}
\end{document}
